Which phase is defined by the separation of sister chromatids and their movement toward opposite poles?

• A. Prophase
• B. Metaphase
• C. Anaphase
• D. Telophase

Answer: (C)

The event described is Anaphase. This is when the sister chromatids, held together at the centromeres, are pulled apart as cohesion proteins are cleaved. The kinetochore microtubules shorten, pulling each chromatid toward opposite poles, while the poles move farther apart as microtubules lengthen elsewhere in the spindle. This separation and migration to opposite ends marks the transition from metaphase to the next stage.

For context: Prophase involves chromosomes condensing and the spindle forming; metaphase has chromosomes aligned at the cell’s equator; telophase features chromosomes arriving at the poles, de-condensing, and the nuclear envelope re-forming. cytokinesis typically follows as the cell splits.